An optimization regarding the structural volume is required in motor vehicles on account of the increasing number of technological components in order to be able to ensure the desired plurality of functions provided by the components. For this reason, large-volume components for air conditioning, known from stationary air conditioning systems in the form of mixing chambers, flow guidance devices, and vortexing devices, cannot be used in motor vehicles on account of the low space conditions.
An additional requirement placed on an air conditioning system of a motor vehicle, which conditions a supplied flow of an air mass, optionally divides it and conducts the individual air mass flows to different areas of the vehicle, consists in loading different air outlets of the air conditioning system according to their position and their function with differently tempered air mass flows. The supplied air mass flow is conducted via the heat exchangers so that the air cools down and is dehumidified, as well as, if necessary, reheated before it is conducted into the passenger compartment. The air is blown in, for example, into the area as well as via openings in the dashboard into the passenger compartment and in addition conducted via outlets directly on the windshield in order to keep it free of condensation or to defrost it.
In generic air conditioning systems regulated on the air side, the air mass flow to be supplied to the passenger compartment is divided into two partial air flows by at least one flap, also designated as a temperature flap. The required temperatures of the air mass flows are adjusted with the aid of the temperature flaps and different regulating mechanisms. A warm air flow is conducted through a hot heat exchanger and heated. At the same time a cool air flow flows around the hot heat exchanger. Both differently tempered partial air flows are subsequently mixed in order to achieve the required target temperature.
In addition, it can be necessary in the air conditioning system of a motor vehicle to branch off a bypass air flow of cooled down and dehumidified, that is, cold, air in the direction of flow of the air to be conditioned after the heat exchanger operated as an evaporator, and to conduct it past the mixing chamber directly to the air outlets, in particular to the air outlets in the dashboard. The bypass air flow of the cold air mass flows through a cold air bypass as another additional flow path in order to cool down in a defined manner with the cold air the blowing-out temperature at the air outlets in the dashboard. This achieves a greater stratification of temperature in the passenger compartment, in particular between the air outlets in the dashboard and in the foot area. The temperatures of the air flows at the different outlets, such as the foot area, the dashboard and the pane ventilation, wherein temperatures deviate from each other, are designated as temperature stratification.
In a construction of the cold air bypass above, the mixing chamber of the air conditioning the cold air bypass should be arranged around the flow paths to the air outlets of the windshield. In order to distribute the cold air uniformly onto the air outlets in the dashboard, the air outlet to the windshield is constructed in two parts, a left and a right outlet, in traditional air conditioning systems. The cold air can be conducted to the two air outlets to the windshield as well as around the two flow conduits running to the air outlets to the windshield in order to make possible a good distribution of the cold air onto the air outlets in the dashboard. The systems known in the prior art have very expensive additional apparatus elements, such as the second air outlet to the windshield and the associated air flaps, as well as components for connection within the system, all of which require more space, expense and also an additional assembly expense, as well as a corresponding maintenance expense. The additional air flaps, as well as their associated drive technology also require an additional expense of the constructively very expensive control means of the air mass flows. Furthermore, the additional installations cause limitations and constrictions of the flow conduits and bring about elevated pressure losses in the air mass flow, which results in an elevated performance requirement, an elevated consumption of energy and a reduction of the efficiency of the air conditioning system, and therefore, of the entire motor vehicle. In addition, the additional installations along with the distinct flow losses also cause great flow noises.
Accordingly, there is a need in the art for an air conditioning system of a motor vehicle available which has a simple construction with a minimal number of required components in order to reduce the space requirement of the system, and to reduce the expenses of manufacture, the material cost, the assembly cost and the maintenance cost. In addition, the pressure losses of the air flows through the system, as well as the energy consumption of the system, are to be minimized while the air performance and the efficiency of the air conditioning system are to be increased. Moreover, the occurring flow noises are to be reduced.